List of top Mathematics Questions on introduction to three dimensional geometry asked in AMUEEE

If origin is the centroid of a $ \Delta PQR $ with vertices $ P(2a,2,6),Q(-4,3b,- 10) $ and $ (8,14,2c) $ , then the value of $ a,b $ and $ c $ are respectively.
Given that the points $ P(3,2, - 4) $ , $ Q(5,4, - 6) $ and $ R(9,8,-10) $ are collinear, the ratio in which $ Q $ divides $ PR $ externally is
The line $ x = my + c $ is normal to $ x^2 = - 4ay $ , if c is equal to
The ratio in which the line segment joining the points $(4, 8, 10)$ and $(6, 10, - 8)$ is divided by xy-plane is
The value of $\lambda$ for which the lines $\frac{1-x}{3}=\frac{y-2}{2\lambda}=\frac{z-3}{2}$ and $ \frac{x-1}{3\lambda}=\frac{y-1}{1}=\frac{6-z}{7}$